Am 08.12.23 um 14:41 schrieb Ilpo Järvinen:
On Thu, 7 Dec 2023, Armin Wolf wrote:The WMI chardev API will be removed in the near future. Reimplement the necessary bits used by this driver so that userspace software depending on it does no break. Signed-off-by: Armin Wolf <W_Armin@xxxxxx> --- drivers/platform/x86/dell/dell-smbios-wmi.c | 163 ++++++++++++++------ 1 file changed, 117 insertions(+), 46 deletions(-) diff --git a/drivers/platform/x86/dell/dell-smbios-wmi.c b/drivers/platform/x86/dell/dell-smbios-wmi.c index 931cc50136de..61f40f462eca 100644 --- a/drivers/platform/x86/dell/dell-smbios-wmi.c +++ b/drivers/platform/x86/dell/dell-smbios-wmi.c @@ -32,7 +35,9 @@ struct wmi_smbios_priv { struct list_head list; struct wmi_device *wdev; struct device *child; - u32 req_buf_size; + u64 req_buf_size; + u32 hotfix; + struct miscdevice char_dev; }; static LIST_HEAD(wmi_list);static int dell_smbios_wmi_probe(struct wmi_device *wdev, const void *context) { - struct wmi_driver *wdriver = - container_of(wdev->dev.driver, struct wmi_driver, driver); struct wmi_smbios_priv *priv; - u32 hotfix; + u32 buffer_size; int count; int ret; @@ -162,39 +225,44 @@ static int dell_smbios_wmi_probe(struct wmi_device *wdev, const void *context) if (!priv) return -ENOMEM; + priv->wdev = wdev; + dev_set_drvdata(&wdev->dev, priv); + /* WMI buffer size will be either 4k or 32k depending on machine */ - if (!dell_wmi_get_size(&priv->req_buf_size)) + if (!dell_wmi_get_size(&buffer_size)) return -EPROBE_DEFER; + priv->req_buf_size = buffer_size; + /* some SMBIOS calls fail unless BIOS contains hotfix */ - if (!dell_wmi_get_hotfix(&hotfix)) + if (!dell_wmi_get_hotfix(&priv->hotfix)) return -EPROBE_DEFER; - if (!hotfix) { + + if (!priv->hotfix) dev_warn(&wdev->dev, "WMI SMBIOS userspace interface not supported(%u), try upgrading to a newer BIOS\n", - hotfix); - wdriver->filter_callback = NULL; - } + priv->hotfix); /* add in the length object we will use internally with ioctl */ priv->req_buf_size += sizeof(u64); - ret = set_required_buffer_size(wdev, priv->req_buf_size); - if (ret) - return ret; count = get_order(priv->req_buf_size); priv->buf = (void *)__get_free_pages(GFP_KERNEL, count); if (!priv->buf) return -ENOMEM; + if (priv->hotfix) { + ret = dell_smbios_wmi_register_chardev(priv); + if (ret) + goto fail_chardev; + } + /* ID is used by dell-smbios to set priority of drivers */ wdev->dev.id = 1; ret = dell_smbios_register_device(&wdev->dev, &dell_smbios_wmi_call); if (ret) goto fail_register; - priv->wdev = wdev; - dev_set_drvdata(&wdev->dev, priv); mutex_lock(&list_mutex); list_add_tail(&priv->list, &wmi_list); mutex_unlock(&list_mutex); @@ -202,6 +270,9 @@ static int dell_smbios_wmi_probe(struct wmi_device *wdev, const void *context) return 0; fail_register: + if (priv->hotfix) + dell_smbios_wmi_unregister_chardev(priv);I don't understand how hotfix -> priv->hotfix is related to this patch nor why it's necessary? Or did you mean to use it also in dell_smbios_wmi_remove() but forgot to add the if (priv->hotfix) there?
I indeed forgot to add the "if (priv->hotfix)" here, good catch.
In any case, it would be better to put that conversion into own patch before this one.
I could also drop the priv->hotfix related changes and instead modify the driver to use devres (devm_get_free_pages() for example). This would also simplify the error handling code. I will send a v2 soon containing the necessary patches.
@@ -211,6 +282,7 @@ static void dell_smbios_wmi_remove(struct wmi_device *wdev) struct wmi_smbios_priv *priv = dev_get_drvdata(&wdev->dev); int count; + dell_smbios_wmi_unregister_chardev(priv); mutex_lock(&call_mutex); mutex_lock(&list_mutex); list_del(&priv->list);
